when logging out the homepage is fetched twice (#5160)

* fix #5153: When logging out the homepage is fetched twice.

The logout request handler may respond with a simple 204-NoContent.
The originating view already contains redirection.
As reported on the forum, some servers don't cope well.

* fix #5153 updated: chose whether to respond with empty response or redirection

Check whether header 'X-Requested-With' is not empty, similar as done in HandleExceptions.php
so actual value of the header may change and not affect this behaviour.

1 files changed, 8 insertions, 1 deletions

diff --git a/app/Http/RequestHandlers/Logout.php b/app/Http/RequestHandlers/Logout.php
index 53f5e87a3c..295a4f1ad6 100644
--- a/app/Http/RequestHandlers/Logout.php
+++ b/app/Http/RequestHandlers/Logout.php
@@ -30,6 +30,7 @@ use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\RequestHandlerInterface;
 
 use function redirect;
+use function response;
 use function route;
 
 final class Logout implements RequestHandlerInterface
@@ -44,6 +45,12 @@ final class Logout implements RequestHandlerInterface
             FlashMessages::addMessage(I18N::translate('You have signed out.'));
         }
 
-        return redirect(route(HomePage::class));
+        if ($request->getHeaderLine('X-Requested-With') !== '') {
+            // Ajax request - send empty response
+            return response();
+        } else {
+            // Form submission - redirect to home page
+            return redirect(route(HomePage::class));
+        }
     }
 }